diff --git a/hub/exports/building_energy/idf.py b/hub/exports/building_energy/idf.py
index a8a465b8..898beb55 100644
--- a/hub/exports/building_energy/idf.py
+++ b/hub/exports/building_energy/idf.py
@@ -104,7 +104,8 @@ class Idf:
     else:
       for building_name in target_buildings:
         building = city.city_object(building_name)
-        self._adjacent_buildings += building.neighbours
+        if building.neighbours is not None:
+          self._adjacent_buildings += building.neighbours
     self._export()
 
   def _sanity_check(self):